hyper-v cpu compatible mode and centos RRS feed

  • Question

  • Hi All,

    I am having a major headache in attempting to start a CentOS 5.6 VM in CPU compatible mode. the host would die as soon as the linux kernel begin to load. If I uncheck the compatible mode in cpu settings, it will work just fine. I am running Windows 2008 R2 (updated). The crash, by the way, didn't generate any hyper-v related errors. The server just simply crashed. The hardware is a Dell R715 with 2x Opteron 6238 and 96GB of RAM. I also have two Dell R815 servers with 2x Opteron 6174, also running Windows 2008 R2. I don't have any problem with centos running in compatible mode. Because the CPU difference 6100 vs 6200, I need to run all my VMs in compatible mode in order to do failover and live migration. Can anyone give me a hint, as where to look? I have completely run out of ideas, as there was no error logged anywhere.

    Thanks in advance!


    • Moved by BrianEhMVP Friday, March 2, 2012 11:57 PM (From:Hyper-V)
    Friday, March 2, 2012 11:05 PM

All replies

  • This should be fixed in Windows Server 2008 R2 SP1.

    This posting is provided "AS IS" with no warranties, and confers no rights.

    Monday, March 5, 2012 3:55 PM
  • It was running Windows Server 2008 R2 SP1 Enterprise, when I encountered this problem.
    Monday, March 5, 2012 9:07 PM
  • When you say the server just crashed - do you mean it blue screened? Locked up? Black screen? Could you be more descriptive?

    Also, you mention no logs - try checking your system failure settings.

    MS changed the defaults so the system reboots automatically rather than stopping and keeping the blue screen displayed. It means that unless you're quick, you can easily miss them.

    To check you failure settings navigate to:

    Control Panel->System and Security->Advanced system settings

    Click advanced tab
    Click the Startup and recovery settings button

    Ensure you are creating a kernel memory dump file. (although with 96GB of memory, I'd set it to create a mini-dump!)

    It sounds to me like a device driver is crashing somewhere. Have you checked you have latest release chipset/network and storage drivers installed on the host windows machine?

    If after checking all of those, the system is still crashing, use windows debugger to analyse your crash dump file, and use !analyse - and it'll normally point you in the right direction to what is going on.

    Friday, March 9, 2012 4:46 AM
  • The system became frozen, as no input is taken, no response to network request. I had to do a cold reboot to get it back. As soon as I got back to the desktop, I checked the event log. nothing was logged between the moment it died and the moment it started to reboot.

    With this issue, I ended up to have Dell swap the processors to the older AMD 61xx. Everything ok now. I am almost certain this is a compatibility problem on Windows/hyper-v side with the newly released processor.

    Sunday, April 22, 2012 7:28 PM